1. Field of the Invention
The present invention relates generally to marine power trains and more specifically to a hybrid marine power train system that can utilize either an internal combustion engine or electric motor for propelling a boat.
2. Discussion of the Related Art
In light of numerous environmental concerns, hybrid vehicles that can be powered at least at times with electrical power instead of relying solely on internal combustion engines are becoming increasingly popular. To date, the most prevalent commercialized examples of this trend are found in the automobile industry.
Some efforts have been made to incorporate hybrid drive technologies into the marine industry. To date, the most prevalent examples have been implemented in only the largest of vessels. For example, various naval vessels incorporate gas turbine engines that drive electrical generators so that the vessels are then solely powered by electrical power from the generators and not directly by the gas turbine engines themselves. As another example, various other vessels such as large barges and cruise ships incorporate diesel-electric systems. Diesel-electric systems use diesel engines that drive electrical generators so that the barges or ships are then solely powered by electrical power from the generators and not directly by the diesel engines themselves.
Because, typically, marine implemented hybrid systems, gas turbine-electric and diesel-electric systems, rely solely on electrical power for propulsion, the generators and/or motors are relatively large to continuously produce electrical power that is used both for propulsion and also for electrical accessory and other needs of the vessel. The sizes of such gas turbine-electric and diesel-electric systems are too large to be incorporated into most vessels or boats in a practical manner.
Nevertheless, many boats, especially large pleasure boats or other boats, can be operated for extended periods of time. For example, when at or near marinas or other mooring locations, boats are often operated for hours at a time despite traveling relatively short distances. As another example, when traversing a no-wake designated portion of a waterway boat engines can operate for extended periods of time at or near idle positions even though only a fraction of the power produced by the engines would be required to suitably propel the boats at no-wake speeds. These and various other situations can lead to more fuel consumption by internal combustion engines and more emissions from such internal combustion engines than might otherwise be necessary.
It is further noted that in various jurisdictions, anti-idling rules and regulations are being proposed and implemented for boats and other watercraft. Some jurisdictions are proposing and implementing rules and regulations that prohibit the use of internal combustion engines, or establish maximum horsepower ratings for internal combustion engines, for certain portions of their waterways.
The prior systems fail to provide a solution to the problem of fuel overconsumption by and emissions from internal combustion engine powered boats.
Accordingly, there is a need for a hybrid marine power train system that can be incorporated into boats that are smaller than large barges and cruise ships. It would also be beneficial to provide a hybrid marine power train system that allows a user to select whether to propel a boat by way of an internal combustion engine or an electric motor, as desired.